A Harmonic Elimination Method For Three-Phase PWM Rectifier To Reduce Computational Complexity

Proportional integral (PI) or proportional resonant (PR) controller are the most popular controllers used to shape the current of voltage sourced converters. Besides, current harmonics are inevitably generated while using a three-phase PWM rectifiers. Since the bandwidth of the controller is usually not fast enough to compensate for the generated harmonics, the harmonics are not removed. Selective harmonic compensation is the most popular for compensation of hormoics. This approach, however, needs a significant time for its calculations, as elimination of each harmonic requires its resonant filter. Moreover, to utilize the average current mode technique, the switching frequency of the converter should be synchronized with the sampling frequency of the analog to digital converter (ADC), and the bandwidth of the current controller, as a rule of thumb, should be limited to one-tenth of the switching frequency. This paper proposes a novel elimination approach which suppresses the harmonics by fewer strive and provides sufficient bandwidth for the controller to be able to eliminate the higher-order harmonics. The proposed method is experimentally verified on a 10 KW three-phase PWM rectifier.